Trailer cover system

ABSTRACT

A unit for returning a cover of a trailer comprising a first portion, a cord, and a spring. The spring is connected to the first portion. The cord having first and second ends, the first end of the cord being connectable to the first portion, the second end of the cord being connected to the cover, and the cord being wrappable around the first portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/261,899, filed Oct. 28, 2005, which is a continuation of U.S. patentapplication Ser. No. 10/664,806, filed Sep. 17, 2003, which is assignedto the assignee of the present application and which is herebyincorporated herein by reference in its entirety for all purposes.

BACKGROUND Field of the Disclosure

This disclosure relates to covers for truck trailers, and moreparticularly to a trailer cover system.

Many truck trailers, particularly those hauling loose loads such as sandand gravel, need a cover to prevent the wind from blowing load particlesoff the load bed. Various apparatus have been devised for covering atrailer load. Some such apparatus include a motor for selectivelywinding a flexible cover. An effective cover should be one which iseasily operated by the truck driver so as to selectively cover anduncover the load from the convenient location of the truck cab. My U.S.Pat. No. 5,031,955, the disclosure of which is hereby incorporated byreference, provides a truck cover which may be conveniently motoroperated from the cab of a truck to extend the cover from a windingassembly proximate the front of the truck bed and toward the rear of thetruck bed.

A need also exists for systems that cover the trailer from side to side.For instance, U.S. Pat. No. 5,328,228 shows a cover for truck bed andcargo. Similarly, U.S. Pat. No. 5,924,758 shows a roll assist mechanismfor tarp systems. My U.S. Pat. Nos. 6,206,449 and 6,527,331, thedisclosures of which are also hereby incorporated by reference, show aside-to-side truck cover system including a pair of arms, each of whichincludes a base and an extension.

One aspect of the present invention is a wall section for a trailer. Thewall section comprises a male end and a female end. The male endincludes a central recess having at least one protrusion on each side ofthe central recess, the protrusions defining respective lateralrecesses. The female end includes a central protrusion having at leastone lateral protrusion on each side of the central protrusion, thecentral protrusion and the lateral protrusions defining respectiverecesses. Accordingly, an object of this invention is to provide anapparatus of the type described above for use on a trailer.

Another object of this invention is to provide an apparatus of the typedescribed above for use in connection with covering the trailer.

Still another object of this invention is to provide an apparatus of thetype described above for use in a system that provides selective,powered control over covering and uncovering the trailer.

Still another object of this invention is to provide an apparatus of thetype described above that utilizes a relatively reduced number of smallcomponents.

Still another object of this invention is to provide an apparatus of thetype described above that minimizes damage done to the apparatus duringloading operations.

These and other objects, features, and advantages of the presentinvention are readily apparent from the following detailed descriptionof the best mode for carrying out the invention when taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood, and its numerousfeatures and advantages made apparent to those skilled in the art byreferencing the accompanying drawings.

FIG. 1 is a front schematic view of a trailer including an apparatusaccording to the present invention for covering the trailer;

FIG. 2 is a rear schematic view of the trailer shown in FIG. 1;

FIG. 3 is an enlarged view of a top rail shown in the portion of FIG. 2designated

FIG. 4 is a perspective view of the top rail;

FIG. 5 is a cross-sectional view of interlocking sections of oneembodiment of a wall of the trailer;

FIG. 6 is a cross-sectional view of the wall sections joined together;and

FIG. 7 is a partial exploded isometric view of a cover return unit, and

FIG. 8 is an isometric view of the cover return unit showing the cordwrapped around one of the halves of the cover return unit andoperatively connected to the cover return unit.

The use of the same reference symbols in different drawings indicatessimilar or identical items.

DETAILED DESCRIPTION

According to various aspects of the present disclosure, With referenceto the drawings, the preferred embodiments of the present invention willbe described. FIGS. 1 and 2 show an arm assembly 10 for a flexible tarpor cover 12 of a truck trailer 13. The arm assembly 10 comprises a base14 and an extension 18. The base 14 is preferably mounted to the trailerat a base plate 20 proximate the top of the front 22 of the trailer.While the base plate 20 is shown in the drawings centered and closer tothe top of the trailer 13, it should be appreciated that the base platemay be mounted at a variety of locations.

The base plate 20 includes at least one spiral torsion spring.Preferably, one end of each of the springs engages a groove formed inthe surface of and extending a substantial portion of the length of acenter shaft, while the other ends of the springs cooperate with alocator pin. Further details of this arrangement are taught by U.S. Pat.No. 5,887,937, which is hereby incorporated by reference. In this way,the base 14 is normally biased clockwise as shown in FIG. 1 across atleast a portion of the front 22 of the trailer from a mostly or fullyuncovered, stowed position, through intermediate positions (only one ofwhich is shown) and toward a deployed position.

The extension 18 is pivotally connected at one of its ends to the base14 by a hinge or knuckle 28. Preferably, a knuckle shaft is welded orotherwise fixed to one of a pair of plates extending from an upper endof the base 14. The knuckle shaft extends through the lower end of theextension 18 such that the knuckle shaft is rotatable with respect tothe extension. One end of each of a plurality of spiral torsion springspreferably engages an axial groove formed in the knuckle shaft. Theother ends of the springs cooperate with a knuckle locator pin. Furtherdetails of this arrangement are taught by U.S. Pat. No. 5,944,374, whichis hereby incorporated by reference.

In this way, the extension 18 is also normally biased clockwise as shownin FIG. 1. Rotation of the extension 18 in both directions may belimited by one or more stops which are preferably in the form of plates29. The plates 29 are welded or otherwise attached to the knuckle 28,and extend inwardly therefrom to engage the extension and preventoverrotation. Another stop may be welded or otherwise attached to thefront 22 of the trailer to limit the pivotal movement of the base 14, astaught by U.S. patent application Ser. No. 09/957,202 filed Sep. 20,2001, the disclosure of which is hereby incorporated by reference.

A motor 30 is mounted on the distal end of the extension 18. A rotatablereel 32 extends from the motor 30, and is operatively connected to oneend of the cover 12 so as to function as a take-up spool. The other endof the cover 12 is clamped, riveted, or otherwise fixed at one or morepoints along a line below the top of one side 34 of the trailer, such asat one or more openings 36 along a top rail 38. As shown in FIGS. 3 and4, the top rail 38 includes one or more metal or plastic pieces, such asextruded or pultruded aluminum or composite fiberglass polymer. The toprail 38, and an opposite top rail 60, include generally depending legs39 and 40 that are adapted to be mounted over the top of the trailerwall 34 or the opposite trailer wall 41. The legs 39 and 40 may be fixedto the trailer walls in any conventional manner, such as by welding,riveting or bolting. The trailer may also be provided with front andrear end caps, which are not shown, in order to provide a uniform wallheight around the perimeter of the trailer, if the front and rear wallsof the trailer are not already high enough.

The top rails 38 and 60 also each include a major interior surface 42, amajor exterior surface 44, and one or more ribs 46, 48, 50, 52 and 54extending from one or both of the surfaces 42 and 44. In a preferredembodiment shown in the figures, the ribs 46, 48, 50 and 52 all meet ata reinforced section 55 proximate the exterior surface 44. A lockingchannel portion 56 of the exterior surface 44 is concave, in order toaccommodate the stowed tarp spool 32 as shown in FIGS. 1 and 2. Theconcave portion 56 of the top rail 38 includes the opening 36, intowhich the stationary end of the tarp 12 may be anchored in any wellknown fashion. In a preferred embodiment, the tarp 12 is attached to thetop rail 38 by sliding a tube 57 through a pocket in the stationary endof the tarp, and then sliding the stationary end of the tarp and thetube through a void 58 in the top rail with the tarp extending throughthe opening 36. The top rail 60, of course, does not require an openingsimilar to the opening 36.

For either of the top rails 38 or 60, the exterior surface 44 preferablyincludes a rounded lip 62 that extends to a point at or below theuppermost extent of the concave surface 56. In the fully uncoveredposition, the cover 12 is wound on the reel 32 until the reel residesgenerally proximate the concave surface 56. In this position, thetrailer may dump rearwardly or in either the clockwise orcounterclockwise direction without interference from the retractedcover.

The motor 30 is preferably provided with a brake which allows, amongother things, for the apparatus 10 to remain in the stowed position. Thelip 62 facilitates retention of the reel 32 in the stowed position. Whenthe brake is released, the base 14 swings toward the driver's side 41 ofthe trailer, and the springs of the knuckle 28 also bias the extension18 clockwise as shown in FIG. 1 toward the side 41 of the trailer so asto hold the cover 12 in tension. The motor 30 may be powered, fromwithin or without the cab of the truck, to facilitate this operation.Further details of one embodiment of the motor are taught by U.S. Pat.No. 5,829,819, which is hereby incorporated by reference. In this way,the cover 12 is pulled off of the reel 32 and extended over the trailer.The motor 30 can be reversed to drive the reel 32 and retract the cover12 against the tension force of the springs to uncover the load bed.

The top rail 60 is provided with a profile generally similar to theprofile of the top rail 38 so that the motor 30 drives the reel 32within the concave portion of the top rail 60, where the lip of the toprail 60 and the motor braking function may be used to hold the cover 12in the deployed position. The top rails 38 and 60 thus allow the tarpreel 32 to reside close to the sides of the trailer in both the openedand closed positions. Because the tarp reel does not rest on the top ofthe trailer when the tarp is opened or closed, the overall height of thetrailer and the possibility of a loader causing harm to the tarpassembly are reduced.

Any rotation of the base 14 less than about 250 degrees is contemplated,and in a preferred embodiment the base sweeps out an arc of about 120degrees. Any rotation of the extension 18 relative to the base 14 isalso contemplated, and in a preferred embodiment the extension rotates atotal of about 250 degrees. By varying the position of the locator pins,the preload of the springs, the number of springs and/or the springconstant of the springs, the forces biasing the base and the extensiontoward the deployed position are variable. In a preferred embodiment,eight springs are used to bias the base 14, and three springs are usedin the knuckle 28 between the base and the extension 18. In thisarrangement the knuckle 28 opens relatively quickly, thus accommodatingthe weight of the axle, cover, and motor 30, and allowing the motor toswing from either its fully covered or uncovered place and clear the toprail 38 or 60.

FIGS. 5 and 6 show interlocking sections 70 and 72 that may be used toform the walls 34 and 41 of the trailer. The sections 70 and 72 aregenerally identical, and of course two or more may be needed to form theextent of a trailer wall, depending upon the length of the sections andthe length of the wall required. The sections 70 and 72 havesubstantially smooth inner and outer sides joined by cross ribs 74. Eachwall section includes a male end 76 and a female end 78. The male end 76of one wall section is adapted to interlock with the female end 78 of anadjacent wall section. In a preferred embodiment, the male ends 76include a central recess 80 flanked by protrusions 82 and 84. Theprotrusions 82 and 84 in turn define respective lateral recesses 86 and88 generally proximate the outer surfaces of the wall sections. Thefemale ends 78 include a central protrusion 90 flanked by lateralprotrusions 92 and 94 generally proximate the outer surfaces of the wallsections. The central protrusion 90 and the lateral protrusions 92 and94 in turn define respective recesses 96 and 98.

When brought together, the lateral protrusions 92 and 94 lockinglyengage the lateral recesses 86 and 88, respectively. At the same time,the protrusions 82 and 84 lockingly engage the recesses 96 and 98, whilethe central protrusion 90 fits within the central recess 80. Thesections 70 and 72 are preferably extruded from aluminum. After the wallsections are preassembled, with or without the top rails, the entirepreassembly may be joined, such as by welding, to the metal rails of thetruck bed. Because the individual wall sections do not need to be weldedtogether, substantial time and effort may be avoided.

Referring again to FIG. 2, an elastic cord may be provided proximate therear of the trailer for biasing the reel 32 toward the driver's side 41of the trailer. More preferably, a cover return unit 100 is provided.The cover return unit 100 is preferably mounted on the driver's side 41of the trailer, at or near the rear of the trailer. As shown in FIG. 7,the cover return unit 100 preferably includes two halves 102 and 104molded in an automotive grade plastic and rotatably mounted on anexternal pivot pin assembly 106, and a large spiral torsion 108contained inside the halves 102 and 104. The pivot pin assembly 106 issecured to the trailer, preferably by bolts extending through holes 110.One end 112 of the spring 108 is secured in a groove 114 in the pivotpin assembly 106, and another end 116 of the spring 108 is secured, suchas by insertion in a groove 118, to the cover return half 102.

A sufficient length of nylon rope or cord 119, shown in FIGS. 2 and 3,is wrapped around the assembled cover return unit 100, with one endattached to the unit itself such as by a cable clamp secured by one ofthe screws extending through holes 120. See FIG. 8. The other end of therope 119 extends through a hole in an end cap secured on the back end ofthe tarp axle 32 such as by screws 122. The rope 119 is preferablyknotted at this end to prevent it from being withdrawn through the holein the end cap of the reel. As the tarp reel 32 rolls toward thepassenger side 34 of the trailer, i.e. uncovering the trailer, the rope119 unspools from the cover return unit 100. As the rope unspools, itrotates the unit 100 to wind the spring 108 and store rotational torque.When the cover 12 is returned to the driver's side 41 of the trailer,the cover return unit 100 pulls on the back of the axle 32 using thetorque stored in the spring 108. In operation the spring 108 isrotatably mounted on the pivot pin assembly 106 about a spring axis 77which is perpendicular to the reel axis 79 about which the tarp reel 32rotates (as shown in FIG. 2, for example). Movement of the rope 119unwraps the cover 12 from the closed position of FIG. 2 wrapped aroundthe reel to any partial or fully opened position (such as shown inFIG. 1) since the rope 119 is operatively connected to the cover 12.During this process, the rope 119 unwinds around the halves 102, 104.Since the rope 119 is operatively connected to the first half 102, thehalves rotate with respect to the pivot pin assembly 106. This rotationurges the spring 108 to rotate about the spring axis 77, producing arotational torque that pulls on the rope 119, in a direction urging thecover 12 toward the closed position. Thus, the cover return unit 100assists with returning the cover 12 to the closed position.

It should be understood that while the forms of the invention shown anddescribed above constitute preferred embodiments of the invention, theyare not intended to illustrate all possible forms thereof. The wordsused are words of description rather than limitation, and variouschanges may be made without departing from the spirit and scope of theinvention disclosed.

1. A cover return unit mounted on a trailer comprising, in combination:a cover movable between an opened position and a closed position,wherein the cover is attached to a reel rotatable about a reel axis, andthe cover is wrappable about the reel; a pivot pin assembly adapted tobe attached to the trailer; a first half and a second half, wherein thefirst half is rotatably mounted on the pivot pin assembly; a cord havinga first end operatively connected to the first half, and a second endoperatively connected to the reel; and a spring attached to the firsthalf and to the pivot pin assembly, wherein the spring is rotatableabout a spring axis that is perpendicular to the reel axis; whereinmovement of the cord urges the cover from the closed position which inturn urges the spring to rotate about the spring axis, producing arotational torque that pulls on the cord in a direction urging the covertoward the closed position.
 2. The cover return unit of claim 1, whereinthe pivot pin assembly includes a groove adapted to receive the spring.3. The cover return unit of claim 1, wherein a part of the cord ispartially wrapped around the first half, and the part of the cordpartially wrapped around the first half and the spring are coplanar. 4.The cover return unit of claim 3, wherein the part of the cord partiallywrapped around the first half is positioned between the first half andthe second half.
 5. The cover return unit of claim 1 wherein the springhas a first end and a second end, the first end of the spring isconnected to the pivot pin assembly and the second end of the spring isconnected to the first half of the cover return unit.
 6. The coverreturn unit of claim 1, further comprising a first top rail and a secondtop rail, wherein the cord makes a right angle turn at each top rail. 7.A cover return unit for a trailer comprising: a cover movable between anopened position and a closed position, wherein the cover is attached toa reel rotatable about a reel axis, and the cover is wrappable about thereel; a pivot pin assembly adapted to be attached to the trailer; afirst half and a second half, wherein the first half is rotatablymounted on the pivot pin assembly; a cord having a first end connectedto the first half, and a second end connected to the reel; and a springattached to the first half and to the pivot pin assembly and rotatableabout a spring axis; wherein movement of the cord urges the cover fromthe closed position which in turn urges the spring to rotate about thespring axis, producing a rotational torque that pulls on the cord in adirection urging the cover toward the closed position.
 8. The coverreturn unit of claim 7, wherein the pivot pin assembly includes a grooveadapted to receive the first end of the spring.
 9. The cover return unitof claim 7, wherein the spring is a torsion spring.
 10. The cover returnunit of claim 7 wherein the spring has a first end and a second end, thefirst end of the spring is connected to the pivot pin assembly and thesecond end of the spring is connected to the first half of the coverreturn unit.
 11. The cover return unit of claim 7, further comprising asecond half of the cover return unit connected to the first half of thecover return unit.